Machines for processing sheets of paper, such as inserters, are well known in the art. A typical inserter may include: a cut sheet feeder module, a web sheet burster module, an accumulator module, a right angle transport module, a folder module, an insert module and a moistener/sealer module. This list is not intended to be exhaustive, but merely illustrative, of the wide range of functionality that is often incorporated into an inserter. Generally, inserter manufacturers custom build each machine to meet the needs of a particular user or customer. As a result, an inserter may be comprised of different arrangements and combinations of modules according to the customer's needs.
Typically, inserters of the kind described above are used in printing, book binding and direct mailing operations. An example of such an inserter is Model 8300 available from Pitney Bowes Inc., Stamford, Conn.
To simplify the manufacturing process the manufactures develop each module as a self contained independent unit or workstation. This provides flexibility during the manufacturing process of an inserter because each module is adapted to easily connect with other modules. For example, one common technique is designing the input end and the output end of every module to be at a fixed horizontal elevation which is uniform for all of the different modules. Thus, the different modules may be easily coupled together because the output end of a first module will be in horizontal alignment with the input end of a second module. However, a notable exception to this arrangement is the folder module.
The folder module contains a series of pairs of folding rollers, buckle chutes, and end stops for folding a single sheet or a collection of sheets. Typically, each pair of folding rollers is offset both horizontally and vertically from the previous pair of folding rollers. Each buckle chute and corresponding pair of feed rollers is responsible for making a single fold in the sheet. The location of the fold along the sheet depends on how far the sheet is feed into the buckle chute and is thus controlled by the position of an adjustable end stop within the buckle chute. Accordingly, the buckle chutes can be arranged to create more than one fold in a sheet.
At each installation different final configurations for the sheet are required. These configurations vary depending on the needs of the user at the time. Examples of a few configurations that users desire to make are: half fold--a single fold that divides the sheet into two equal portions, C fold--a combination of two folds that divide the sheet into three substantially equal portions with the folded ends angled inward toward each other and Z fold--a combination of two folds that divide the sheet into three substantially equal portions with the folded ends angled away from each other. Additionally, other configurations may be desired which require three or four folds. Thus, the folder module must be capable of producing a wide variety of folds and also be flexible so as to adapt to new folding requirements. To accomplish this, the folder module includes adjustments which control the number of buckle chutes that the sheet encounters and also the distance that the sheet travels into each buckle chute. As a result, any desired configuration may be obtained.
After the sheet or sheets have been folded into the desired configuration, it is desirable to then feed them downstream to another module in the inserter for further processing. Therefore, the need exists to operatively connect the output end of the folder module with the input end of the downstream module so that the sheet is automatically fed downstream. Generally, the input end of the downstream module is located at only one fixed horizontal elevation. In contrast, the output end of the folder module will be at one of several different horizontal elevations depending upon the desired fold configuration. Thus, the sheet will necessarily be output by different pairs of folding rollers. This fact greatly complicates operatively connecting the output end of the folder module to the input end of the downstream module because their respective horizontal elevations are different.
Prior art systems seek to solve this problem by a variety of techniques. One approach is to determine which pair of folding rollers the sheet will exit from to achieve a desired fold configuration and then raising or lowering the folder module accordingly until the output from a selected pair of rollers is in horizontal alignment with the input end of the downstream module. To achieve this, the folder module is placed on an elevator or platform so that it can be raised or lowered. Although this approach solves one problem it creates another. By raising or lowering the folder module the output end of the folder module is now in horizontal alignment with the downstream module, however, the input end of the folder module is no longer in horizontal alignment with the output end of a first upstream module. To solve this newly created problem the first module upstream from the folder module is also placed on the elevator and raised or lowered along with the folder module. Similarly, it can be appreciated that this problem is now repeated between the first upstream module and every other module upstream from it. Thus, for the problems to ultimately be solved every module upstream from the folder module must also be adjusted vertically along with the folder module. In addition to being costly, this arrangement is also time consuming.
Another prior art system, disclosed in U.S. Pat. No. 2,230,168, entitled BUCKLING FOLDING MACHINE, takes a different approach. It teaches a device on the output end of the folder module which is mounted to the last buckle chute to be used. However, if the last buckle chute to be used changes, then the device must be uninstalled completely and next reinstalled at the new location. As in the other prior art system, this arrangement is time consuming to reconfigure.
Accordingly, there is a need for an adaptable and flexible system that allows the output of a folder module to be connected to the input end of the downstream module easily, quickly and cost effectively without disturbing the upstream modules.